Improvement in expanding pulleys



D. T-HOMAS,-T. TAYLOR &- T. H. BURRIDGE'.

Expanding Pulley. No. 211,356. 7 ,.Paieh ted m. 14.1 79,

7 III, a

DAVID THOMAS, THOMAS TAYLOR, AND THOMAS H. BURRIDGE, or sr.

' LOUIS, MISSOURI.

lMPFiOh/EMENT IN EXPANDING PULLEYS.

Specification forming part of Letters Patent No. 211,356, dated January 14, 1879; application filed September 27, 1878.

To all whom it may concern:

Be it known that we, DAVID THOMAS, THOMAS TAYLOR, and TnoMAs H. BURRIDGE, all of the city of St. Louis, in the State of Missouri, have invented a certain new and useful Improvement in Expanding Pulleys, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification. A

Our invention relates to certain improvements in the construction of expanding pulleys.

Pulleys constructed according to our invention have a flexible periphery, consistin g of a number of sections fitted together, with lap expansive joints, as shown, so that the beltsurface will be continuous all around the periphery. I

To the inner side of both ends of each section is attached a bar, extending the whole width of the periphery, and bearing against the inner side of the next section. One end of each section is made movable upon a bearing-block at the end of the pulley-spoke, and the other end of each section is attached to the next spoke, so that each section slides at one end upon the bearing at the end of a spoke. The arrangement is such that each section is sprung into the proper curve as the periphery of the pulley is expanded and contraeted.

The means of adjustment consists in making the inner ends of the spokes of proper form to slide in suitable radial mortises of the hub, and each having a pin working in a radial slot, and extending through an inclined slot in a cam-collar turned upon the hub by a screw-gear.

In the drawings, Figure 1 is a perspective View of an expanding pulley constructed according to our invention. Fig. 2 is an end view of the hub of a pulley, with part in sec tion.

The expanding pulley is constructed as follows: K is the hub, having a number-say six, more or less-of radial mortises, k, with radial slots 70, through which extend pins or studs 1 upon the sides of the spokes L. These pins l also extend through inclined slots m in a turning canrplate, M. The inclination of the slots m is such that as the cam-plate M is turned the spokes are moved inward or outward in the hub. 7

At the periphery of the cam-disk M is a screw-gear, in, which is engaged by a gearscrew, N, sothat by the turning of the screw the cam-disk is turned. The screw serves to hold the cam-disk and the spokes to their positi on when adjusted.

At the end of each spoke is a bearing plate or block, 0, to which is attached one end. of one of the sections I, which sections together constitute the periphery of the pulley.

The attachment of the section to the spoke is made through means of a bar, 1), to which the end of the section is fastened, and which is in turn attached to the spoke end 0. The opposite end of each section (to that which is fixed to the spoke) is attached to a bar, similar to that p.

The bar 12 is not fixed rigidly to the block 0, but is capable of sliding thereon as the periphery of the pulley is expanded or contracted.

The connection between bar 12 and the'block O is by means of bolts 12 which pass through slots 0 in the blocks.

The ends of the sections 1? are recessed, so as to interlock, as shown, the extension 22 of one section occupying the recesses of the other, and the bars 19 p are attached to the extreme ends of the extension.

The outer bearing-surface of the block 0 is such that as the pulley=periphery is expanded or contracted the pressure of the block upon the bar 1), taken in connection with the pressure of the bar 19 upon the extensions 19 will cause the section to take the proper curve in the are of a circle equal in circumference to the pulley.

We claim as our invention-- 1. The combination, in an expanding pulley, of the radially-adjustable spokes L and rim formed of flexible sections 1 having interlocking ends 19 as and for the purpose set forth.

2. The combination, in an expanding pulley, of the adjustable spokes L, slotted camdisk M, adjusting screw-gear m at the pedisk M, spokes L, with pins l and blocks 0,

and the flexible rim, composed of sections P, bearing upon the blocks 0, for the purpose set forth.

DAVID THOMAS. THOMAS TAYLOR. THOMAS H. BURRIDGE. Witnesses:

SAML. KNIGHT, WILLIAM EVANS, 

